WHEAT. 

 ('OMMON WhBATS. 



237 



Early and Late Wheats. — From a practical point of 

 view a classification on relative dates of maturity is important, 

 e.g., on irrigated land in the Transvaal the late wheats must 

 be sown during May, while the early wheats should go in later 

 and may be sown up to the end of July. A late wheat sown 

 late will mature early in December, a period when rust is at 

 its worst ; if sown very late the crop will probably be destroyed 

 by rust before maturing. In colder countries these are known as 

 spring and winter wheats. On these, Percival' makes the fol- 

 lowing interesting observations : "At Reading, where the 

 average minimum winter temperature rarely falls below -3° 

 or -4° C, I have always sown all kinds of wheats in autumn 

 and have rarely observed any damage by frost, even among 

 the most delicate kinds. 



" There is, however, considerable difference among 

 wheats in regard to their resistance to frost, some being 

 ki'led outright by temperatures which others will withstand 

 without, damage. 



" Many wheats are little injured at -10° to -15° C, but 

 suffer when the temperature falls much below this. 



" In cold climates the difference are readily determined, 

 and farmers term the sorts which can be sown in autumn 



